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["Rapid" serology for the diagnosis of Helicobacter pylori infection. Evaluation of its accuracy compared with a gold-standard and its concordance with "classic" serology].

AIM: To prospectively evaluate the validity of a rapid office-based diagnostic serological test (using capillary blood) in our population, taking as reference a combination of standard diagnostic methods, as well as to compare the results of this technique with those of "classic" serological tests (using venous blood). PATIENTS AND METHODS: We prospectively studied 39 consecutive patients with symptoms of the upper digestive tract who had undergone oral gastroscopy. Gastric biopsies were taken for histology and rapid urease testing, and a 13C-urea breath test was performed. An enzyme-linked immunoassay that detects IgG antibodies against Helicobacter pylori was used as a "classic" serological test and the commercial kit FlexPack HP was used as a "rapid" serological test. The endoscopist, the pathologist and those responsible for reading the rapid urease test, the 13C-urea breath test and both serological tests did not know the results of the other diagnostic methods. Patients were considered H. pylori positive when at least two of the three validated tests (rapid urease test, histology, and 13C-urea breath test) revealed infection and were considered free of infection when all tests were negative. RESULTS: Thirty-nine patients were studied. Thirty-eight per cent were male (mean age 48 +/- 15 years). The prevalence of H. pylori infection detected by the gold standard was 69.2%. The sensitivity and specificity of the "classic" serological test was 96% 95% (CI: 79-99) and 91% (59-100). "Rapid" serological testing was positive in nine patients, negative in 28 and indeterminate in two. A single digital puncture was sufficient in 80% of the patients, 15% needed two and 5% needed three. Most patients (77%) had no preference for either type of serological test while 20.5% preferred digital puncture and 2.5% venous puncture. The sensitivity, specificity, positive predictive value and negative predictive value were 31% (16-50), 91% (59-100), 89% (52-100) and 36% (19-56) respectively. Sensitivity was unaffected by age but specificity was lower in patients older than 40 years (89% vs. 100%; McNemar's test: 8; p < 0.01). Kappa's coefficient between the "classic" and the "rapid" serological tests was 0.16 (SE 0.1) and McNemar's test was 12.2 (p < 0.001), which indicates that the prevalence of infection diagnosed by both methods was not homogeneous. CONCLUSION: The "rapid" office-based serological test used in our study is of insufficient diagnostic accuracy to be used in clinical practice to identify H. pylori infection.

Enzyme-Linked Immunosorbent Assay↗

Rapid serological profiling by enzyme-linked immunosorbent assay. IV. Association of infectious bursal disease serology with broiler flock performance.

Breeder and broiler flocks were serologically evaluated using a multiple enzyme-linked immunosorbent assay (M-ELISA). The serologic status of two commercial broiler-breeder flocks and their progeny was monitored, and 840 sera were promptly assessed for antibodies against six infectious agents using the M-ELISA. Breeder flocks were sampled at lay, and broiler chicks were hatched from fertile eggs collected on the scheduled lay date of the breeders. The broiler chicks were placed for growout as eight separate flocks (four from each breeder), and the serologic survey of broilers included sequentially sampling each flock five times between 1 day of age and market. Association of broiler vaccination schedules, mortality, and condemnation data with the temporal serologic data obtained indicated that the earlier appearance of active antibody against infectious bursal disease (IBD) in some unvaccinated flocks was associated with subsequent higher growout mortality and with the poorer overall performance that these flocks experienced. The results of this serologic survey also demonstrated that if a constant, well-timed monitoring program had not been used, major serologic differences between flocks would not have been detected. Serologic profiles of selected broiler flocks by virus-neutralization (VN) tests for infectious bronchitis virus (IBV) and reovirus or by hemagglutination-inhibition (HI) tests for Newcastle disease virus (NDV) compared favorably with the serologic profiles obtained by M-ELISA. Comparison of vaccination histories with serologic results derived from M-ELISA, VN or HI tests indicated that response to vaccination for IBV and NDV at 1 day was either blocked or significantly delayed by moderate levels of maternal antibody and/or were suppressed by an apparent field outbreak of IBD that occurred in all eight broiler flocks.

Animals↗

Towards a unified theory for immunogenetic systems. I. Probing the serologic field--a meta-serologic approach.

A serologic field (SEF) is produced by the in vitro studies of antibody-antigen interactions and usually includes serologic information processing (SIF). SIF can be regarded as the process whereby essentially "meaningless" raw data or experimental observables emanating from an input reality are structuralized and hence falsified into a "meaningful" pattern, Gestalt or output image. According to this "black box model", different "fact categories" (FC) can be identified in SEF. Traditional serology generally confounds its FC whereby fact category mistakes (FCM) are produced. Some FCM are structurally similar to the description of "mice" as four-letter animals or as a four-legged word--i.e. facts about "thing-properties" (animals, legs) are confounded with facts about "language-properties" (letters, words). In SEF, antibody and antigen molecules (thing-properties) are similarly endowed with "empty symbols" (language-properties). Due to such FCM, radically new meanings are assigned to experimental observables if the serologic language and/or theory is changed. The present meta-serologic approach consists of the design of a meta-serologic symbol language (SL-2) which includes the contemporary (simple-complex) conceptual framework (language and theory) as a limiting case. Consequently, some truly radical and revolutionary Gestalt switches will be generated when a specified SEF is mapped onto SL-2.

Antigen-Antibody Reactions↗

Serologic screening before endoscopy: the value of Helicobacter pylori serology, serum recognition of the CagA and VacA proteins, and serum pepsinogen I.

BACKGROUND: We wanted to assess the diagnostic value of pre-endoscopy screening by Helicobacter pylori serology, serum recognition of the CagA and VacA proteins, and serum pepsinogen I levels (sPGI) in patients up to 55 years of age with uncomplicated simple dyspepsia. METHODS: Consecutive dyspeptic patients referred for open-access endoscopy, excluding patients with alarm symptoms, recent intake of acid suppressants, or ingestion of non-steroidal anti-inflammatory drugs. H. pylori status was determined by histology and urease testing. H. pylori serologic status was determined with the enzyme-linked immunosorbent assay (ELISA) and Western blotting, serum recognition of CagA and VacA with Western blot, and sPGI levels by radioimmunoassay. RESULTS: One hundred and fifteen patients were studied (mean age, 40 years: range, 20-55 years), of whom 58 were H. pylori-positive in biopsy-based tests. Twenty-one patients (18%) had significant gastroduodenal lesions (erosions, ulcers, or cancer). The sensitivity (specificity) of the ELISA (optimized) and Western blot in determining H. pylori status was 94.8% (89.5%) and 100% (96.4%), respectively. Screening strategies based on the ELISA or Western blot for determining H. pylori serologic status would have detected 95% or 100% of significant lesions, respectively, and each 'saved' 47% of endoscopies for simple dyspepsia. Serum recognition of the CagA protein would have detected 95% of significant lesions and 'saved' 55% of endoscopies, whereas recognition of the VacA protein would have detected only 81% of the lesions. Screening by H. pylori serology plus a 'low' (<55 ng/ml) or 'high' sPGI (>125 ng/ml) would detect only 57% of significant lesions, although the only case of cancer was included in the hypopepsinogenaemic subgroup of just 11 patients. CONCLUSIONS: In patients with uncomplicated, simple dyspepsia up to 55 years of age, screening by H. pylori serology identified 95%-100% of patients with significant gastroduodenal lesions while potentially saving 46.9% of endoscopies. Serum recognition of the CagA protein identified 95% of lesions and would have saved an additional number of endoscopies (7.9%) compared with basic serology. Measurement of sPGI was of limited diagnostic value.

Adult↗

Biologic false-positive serologic tests for syphilis and other serologic abnormalities in autoimmune hemolytic anemia and thrombocytopenic purpura.

Autoimmune hemolytic anemia (AIHA), the first autoimmune disease to be recognized, is a manifestation of defective immune regulation. Although often associated with a lymphoid neoplasm or an overt immunologic disorder, AIHA frequently appears without apparent cause. Many patients with the "idiopathic" disease have been found to have various immunologic abnormalities in addition to the antibodies reacting with red cells. Although familial AIHA is uncommon, other autoimmune diseases and serologic abnormalities have been encountered in relatives of numerous patients. Few detailed family studies have been performed, but the available data suggest that predisposition to AIHA and to the associated immunologic disorders often is genetically transmitted. Less information is available about autoimmune thrombocytopenic purpura, in part because of the historic difficulty in recognizing autoantibodies that react with platelets. However, there is good evidence for genetically determined predisposing factors in some cases. Using the BFP reaction as an indicator, we add to the evidence that AIHA and autoimmune thrombocytopenia, like SLE, tend to occur in persons with a long-standing occult immunologic defect that often has a genetic basis. In our studies, 11 patients with AIHA or ITP had BFP reactions. The serologic abnormality in 4 had been known to precede the blood disorder by 6 to 44 years. Five of the patients had an additional disease believed to have an immunologic pathogenesis. Serologic abnormalities apart from the BFP reaction and the red cell or platelet antibodies were demonstrated in 9. Autoimmune diseases or serologic changes are known to have affected relatives of 5 patients, including 4 who had 1 or more relatives with BFP reactions. Serologic tests for syphilis were negative in 2 sibs with autoimmune thrombocytopenic purpura whose father had a chronic BFP reaction and thyroiditis, but all 3 had low levels of IgA and IgM. Lymphoproliferative disorders appeared in 3 of the patients with BFP reactions, and 2 had relatives with lymphoid neoplasms. A lymphoma occurred in a woman with cold agglutinin disease 21 years after the discovery of the erythrocyte antibody. Our observations support the view that an abnormality of cells of the immune system, often genetically determined, may predispose to serologic changes, immune deficiency, autoimmune diseases and neoplasia.

Adult↗

Rapid DNA typing for HLA-C using sequence-specific primers (PCR-SSP): identification of serological and non-serologically defined HLA-C alleles including several new alleles.

Detection of HLA-C antigens by complement mediated cytotoxicity using human alloantisera is often difficult. Between 20 to 40% of individuals in every race have undetectable HLA-C locus antigens and 9 out of the 29 sequenced HLA-C alleles so far published encode serologically undetected antigens. In addition, HLA-C molecules are expressed at the cell surface at about 10% of the levels of HLA-A and HLA-B. Recently, amplification of DNA using sequence-specific primers (PCR-SSP) has proved a reliable and rapid method for typing HLA-DR, HLA-DQA and HLA-DQB genes. PCR-SSP takes two hours to perform and is therefore suitable for the genotyping of cadaveric donors. We have designed a set of primers which will positively identify the HLA-C alleles corresponding to the serologically defined series HLA-Cw1, Cw2, Cw3, Cw4, Cw5, Cw6, Cw7 and Cw8. The serologically undetectable alleles have also been detected in groups according to sequence homology. In addition, three new unsequenced variants have been identified. DNA samples from 56 International Histocompatibility Workshop reference cell lines and 103 control individuals have been typed by the HLA-C PCR-SSP technique. 4/56 cell line types and 11/103 normal control individuals types were discrepant with the reported serological types. All combinations of serologically detectable and most of the serologically blank HLA-C antigens can be readily identified. DNA typing for HLA-Cw by PCR-SSP can take as little as 130 minutes from start to finish, including DNA preparation.

Alleles↗

False-positive legionella titres in routine clinical serology testing detected by absorption with campylobacter: implications for the serological diagnosis of legionnaires' disease.

A simple absorption step using blocking fluid prepared from a selected campylobacter strain was introduced in parallel with routine legionella serology tests. Over 12 months, 2716 patients were tested for legionella antibodies by the Indirect Fluorescent Antibody Test of whom 58 (2.1%) had a positive titre (> or = 16) in one or more sera. Campylobacter blocking fluid significantly reduced the legionella titres in 17 of these patients (29%) including four patients with diagnostic serology results (two of whom had pneumonia) and 13 patients with non-diagnostic titres. Absorption with campylobacter however had no effect on the legionella titres in 10 patients with positive serology, in whom legionnaires' disease had been confirmed by culture of Legionella pneumophila from sputum or detection of legionella urinary antigen by ELISA. These results indicate that the serological cross-reaction between legionella and campylobacter is encountered in routine legionella serology tests. The important implications for the diagnosis of legionnaires' disease are discussed.

Campylobacter↗

Widespread circulation of Alongshan virus in Austria and serological evidence for infection in humans: a nationwide molecular and serological observational study.

BACKGROUND: Alongshan virus, a segmented RNA virus in the Jingmenvirus group of flaviviruses, was first identified in 2017 in China in patients with tick-borne encephalitis-like illness. Alongshan virus has since been detected in ticks and mammals in several European countries. In this study, we aimed to characterise the temporal and geographical distribution of Alongshan virus in Austria through nationwide tick surveillance combined with serological and molecular screening in individuals with suspected tick-borne encephalitis or tick exposure. METHODS: In this nationwide molecular and serological observational study, we conducted a PCR-based screening of ticks collected across Austria in 2024, using flagging, animal hosts, and citizen submissions. We also collated genomic data from stored nucleic acid extracts from ticks collected in Austria in 2005 and 2013 in previous surveillance studies and stored extracts of paired tick-human samples collected between 2015 and 2018. Alongshan virus-positive tick samples were subjected to whole-genome sequencing and phylogenetic analysis. In addition to tick samples, blood samples from Austrian patients with reported tick bite or suspected tick-borne encephalitis, submitted to the National Reference Center for Human Arbovirus Infections, Austria, were screened for Alongshan virus infection and subjected to serological and molecular testing. FINDINGS: 2952 ticks were collected between Feb 1, 2024, and Dec 6, 2024, from 29 (83%) of 35 NUTS-3 regions in Austria; the median detection rate for Alongshan virus was 1&#xb7;2% (IQR 0&#xb7;4-3&#xb7;5). In addition, 1816 archived tick samples were analysed, with three testing positive for Alongshan virus. For the virus-positive samples, phylogenetic analysis showed that sequences from Austria grouped within the European clade, with Austrian sequences from the same region showing high sequence similarity. 1361 human serum samples collected between March 1, 2023, and May 16, 2025, were assessed for anti-Alongshan virus IgG antibodies. Two individuals had high antibody titres against Alongshan virus proteins VP1a and VP2. INTERPRETATION: Our study shows detection of Alongshan virus in archived tick samples dating back to 2005, representing the earliest documented occurrence of the virus to date and suggesting that Alongshan virus has been circulating in Austria for at least two decades. The detection of Alongshan virus-specific antibody titres in two individuals suggests past infection and previously unrecognised exposure. These results highlight the need for continued molecular surveillance of tick populations and serological monitoring in humans to define the epidemiology and public health relevance of Alongshan virus in Europe. FUNDING: One Health surveillance and Vector monitoring for cross-border pathogens (OH SURVector) and UNITED4Surveillance.

Adolescent↗

The serological responses of calves to live Salmonella dublin vaccine--a comparison of different serological tests.

The serological responses to live Salmonella dublin vaccine was assessed in three groups of calves; three-day-old colostrum-deprived (3DO C-), three-day-old colostrum-fed (3DO C+) and three-month-old (3MO), by the following tests; serum agglutination test (SAT), indirect haemagglutination test (IHA), complement-fixation test (CFT) and antiglobulin test (AGT). Serological activity was detected by all the tests in the 3MO calves. In the 3DO C+ calves no serological activity was detected by either the somatic SAT or IHA but low levels of CF and somatic AGT antibodies were produced. In 3DO C- calves serological activity, often at low levels, was detected by all the tests except the somatic SAT. High levels of flagellar agglutinins were detected in both groups of 3DO calves. It was concluded that with the exception of the flagellar SAT the tests were affected by the age of the calf and in 3DO calves also by the presence of colostral antibodies. However, the use of the SAT in 3MO calves would provide an indication as to the potency of salmonella vaccines.

Agglutination Tests↗

Serologic survey of Neospora caninum infection in a closed dairy cattle herd in Maryland: risk of serologic reactivity by production groups.

Prevalence of antibodies to Neospora caninum was determined in a cross-sectional consensus survey of 1029 bovines in a dairy herd with endemic Neospora-induced abortion. Sera were screened by indirect fluorescent antibody test (IFAT). The prevalence of N. caninum antibody in the IFAT was 17.9% in 107 neonates, 26.2% in 233 yearling heifers and steers, 39.07% in 218 mature heifers, and 26.9% in 465 milking cows. Serologic reactivity was associated with production grouping on the farm with the greatest risk of serologic reactivity appearing in the yearling and mature heifers. There was an increasing risk of serologic reactivity with increasing age only in the parity one and greater animals in the herd. Castrated males were at half the risk of similarly aged females of possessing antibodies to N. caninum. There was no clear relationship between the serologic status of dams and offspring.

Abortion, Veterinary↗

Serological testing for campylobacteriosis with sera forwarded for Salmonella and Yersinia serology.

Single serum specimens forwarded for Salmonella and Yersinia serology, from a total of 250 patients, were tested for anti-C. jejuni antibodies of the IgG class. Anti-Salmonella and anti-Y. enterocolitica O3 antibodies were examined by a microagglutination test and anti-C. jejuni antibodies by ELISA against a C. jejuni ultrasonicate before (ELISA) and after neutralization of antibodies which cross-reacted with Helicobacter pylori antigens (ELISA-Abs). Blood donor sera (n = 50) and sera (n = 40) from patients with various infectious diseases served as controls. A positive test for anti-Salmonella antibodies was recorded in 4/250 (1.6%) of the patients, for anti-Yersinia antibodies in 7/250 (2.8%), and for anti-C. jejuni antibodies in 7/250 (2.8%) in the ELISA; in 25/250 (10%) in the ELISA-Abs. No mixed infection was recorded by the serological testing. The ELISA-Abs showed a diagnostic specificity of 97.7%. Our results support the inference that diagnostic serology for enteropathogenic bacteria should include serology for C. jejuni, preferably by tests which exclude participation by antibodies which cross-react with H. pylori antigens.

Antibodies, Bacterial↗

Serological and clinical findings in patients with serological evidence of reactivated Epstein-Barr virus infection.

IgM directed against Epstein-Barr virus (EBV) early antigen (IgM-EA) has been established as an early marker of EBV infection and IgG directed against Epstein-Barr virus nuclear antigen I (IgG-EBNA-1) as a late marker. Simultaneous seropositivity to IgM-EA and IgG-EBNA has therefore been proposed as indicating reactivation of latent EBV infection. We have studied 191 patients with serological evidence of reactivated EBV infection with regard to clinical presentation, antibodies directed against EBV viral capsid antigen (IgM-VCA, IgG-VCA), cytomegalovirus (IgM-CMV), human herpesvirus 6 (IgM-HHV-6). IgM rheumatoid factor (IgM-RF), anti-nuclear or anti-cytoplasmic antibodies (ANA/ACA), and total IgM. The clinical manifestations varied considerably, but a diagnosis was established in 121 of the patients. The diversity of the clinical diagnosis probably reflects common reasons for requesting an EBV serological test rather than clinical manifestations of reactivated EBV infection. Only 5.8% of the patients with "serological EBV reactivation" gave a positive result for IgM-VCA. We conclude that "serological EBV reactivation" does not represent an entity relating to clinical manifestations, but probably reflects a non-specific activation of the immune system.

Antibodies, Viral↗

Comparative study of Kaposi's sarcoma-associated herpesvirus serological assays using clinically and serologically defined reference standards and latent class analysis.

Accurate determination of infection with Kaposi's sarcoma-associated herpesvirus (KSHV) has been hindered by the lack of a "gold standard" for comparison of serological assays used to estimate KSHV prevalence in serosurveys conducted in different settings. We have evaluated the performance of five in-house (developed at University College London [UCL], United Kingdom, and at the virology laboratory of the Instituto de Medicine Tropical [IMT] in Sao Paulo, Brazil) and two commercial (ABI and DIAVIR) serological assays to detect antibodies to latency-associated nuclear antigen (LANA) and to lytic KSHV antigens. We used a variety of serum samples assembled to represent populations likely to be at high, intermediate, and low risk of KSHV infection in Brazil. Composite reference standard panels were prepared based on clinical and serological parameters, against which assay performances were assessed using conventional Bayesian statistics and latent class analysis (LCA). Against the clinical reference standard, in-house immunofluorescence assays to detect anti-LANA antibodies (IFA-LANA) produced at UCL and IMT had similar performances, with sensitivities of 61% (95% confidence interval [CI], 48% to 74%) and 72% (95% CI, 58% to 83%) and specificities of 99% (95% CI, 94% to 100%) and 100% (95% CI, 96% to 100%), respectively, and only the IMT IFA-LANA was included in LCA, together with the IMT IFA-lytic and four enzyme-linked immunosorbent assays (ELISAs). The LCA indicated that the IMT whole-virus ELISA performed best (sensitivity, 87% [95% CI, 81% to 91%]; and specificity, 100% [95% CI, 98% to 100%]), confirming the results obtained with the conventional statistical approach. Commercially available ELISA-based tests yielded the lowest specificities using a spectrum of serum samples. The evaluation of KSHV serological assays is warranted before planning serosurveys in various settings.

Antibodies, Viral↗

[Significance of the "isolated anti-HBc" serological pattern determinated by the serological response to the vaccination against Hepatitis B].

Frequently Blood Bank donors are found to have a presence of Total Anti-Bc in the serum in the absence of the Hepatitis B surface antigen (HBsAg) and the Hepatitis B Surface Antigen (Anti-Bs) antibody. This study was designed to determine the serological response to the vaccination against the Hepatitis B virus, and evaluate the effectiveness of the vaccine in such cases, taking into consideration that the protective antibody titers for Hepatitis B are measured in levels above 10 mUl/ml.Thirty-one patients with the HBsAg negative/Anti-Bs negative/Antil-Bc positive serological patterns received three doses of the recombinant DNA vaccine (Hepavax Gene 20 microg), in a 0, 1, 2 months vaccination schedule. Anti-HBs levels were taken 30 days after the application of the last dose. After the 3 doses of the vaccine, the Anti-HBs levels were > 100 mUl/ml in 89% of the cases, > 500 in 50% and > 1000 in 14.3% of the vaccinated patients. Only 3 patients (9.7%) did not show serological response 30 days after the application of the last dose of the vaccine. In conclusion, 90% of the patients administered the HBsAg negative/Anti-HBs negative/Anti-HBc positive serological patterns, obtained Anti-HBs levels considered protectors ( > 10 mUl/m).

Adult↗

Serologic herpes testing in the real world: validation of new type-specific serologic herpes simplex virus tests in a public health laboratory.

BACKGROUND: Serologic testing for herpes simplex virus type-2 (HSV-2) is being implemented in sexually transmitted disease (STD) clinics. GOAL: To determine the performance characteristics of two HSV-2 type-specific serologic assays in a public health laboratory. STUDY DESIGN: Sera stored from a cross-sectional study were tested with the Meridian Diagnostics and Focus Technologies HSV-2 ELISA tests and a type-specific strip immunoblot assay (Chiron Corp.) was used as the reference standard. RESULTS: Prevalence of HSV-2 infection in this sample was 44%. Compared to the reference standard, the sensitivity of the Meridian Diagnostics HSV-2 test was 95.5% (95% CI 83.3, 99.2) and specificity was 98.2% (95% CI 89.0, 99.9). The Focus Technologies test yielded 97.7% (95% CI 86.5, 99.9) sensitivity and 94.5% (95% CI 83.9, 98.6) specificity. CONCLUSIONS: The performance of these HSV-2 type-specific serologic assays was adequate to support their use in high prevalence populations, such as STD clinic patients.

Adolescent↗

Efficacy of several serological tests and antigens for diagnosis of bovine brucellosis in the presence of false-positive serological results due to Yersinia enterocolitica O:9.

Yersinia enterocolitica O:9 bears a smooth lipopolysaccharide (S-LPS) of Brucella sp. O-chain A+C/Y epitopic structure and is a cause of false-positive serological reactions (FPSR) in standard tests for cattle brucellosis. Brucella S-LPS, cross-reacting S-LPSs representing several O-chain epitope combinations, Brucella core lipid A epitopes (rough LPS), Brucella abortus S-LPS-derived polysaccharide, native hapten polysaccharide, rough LPS group 3 outer membrane protein complexes, recombinant BP26, and cytosolic proteins were tested in enzyme-linked immunosorbent assays (ELISA) and precipitation tests to detect cattle brucellosis (sensitivity) and to differentiate it from FPSR (specificity). No single serological test and antigen combination showed 100% sensitivity and specificity simultaneously. Immunoprecipitation tests with native hapten polysaccharide, counterimmunoelectrophoresis with cytosolic proteins, and a chaotropic ELISA with Brucella S-LPS were 100% specific but less sensitive than the Rose Bengal test, complement fixation, and indirect ELISA with Brucella S-LPSs and native hapten or S-LPS-derived polysaccharides. A competitive ELISA with Brucella S-LPS and M84 C/Y-specific monoclonal antibody was not 100% specific and was less sensitive than other tests. ELISA with Brucella suis bv. 2 S-LPS (deficient in C epitopes), Escherichia hermannii S-LPSs [lacking the contiguous alpha-(1-2)-linked perosamine residues characteristic of Y. enterocolitica S-LPS], BP26 recombinant protein, and Brucella cytosolic fractions did not provide adequate sensitivity/specificity ratios. Although no serological test and antigen combination fully resolved the diagnosis of bovine brucellosis in the presence of FPSR, some are simple and practical alternatives to the brucellin skin test currently recommended for differential diagnosis.

Animals↗

Development of pertussis serological potency test. Serological assessment of antibody response induced by whole cell vaccine as an alternative to mouse protection in an intracerebral challenge model.

The current potency test for pertussis vaccines, the mouse protection test (MPT), has many disadvantages. However, no alternative is yet available. The purpose of this study is to develop a serological alternative for the MPT based on in vitro assessment of the humoral immune response against pertussis in mice. After immunization with pertussis whole cell vaccine, the MPT shows a normal primary and secondary antibody response. Moreover, the i.c. challenge has a distinct booster effect on the pertussis IgG response. The relationship between the concentration of IgG antibodies against the surface-antigens of pertussis bacteria and the survival of mice after the i.c. challenge was demonstrated in a modified MPT (R = 0.91). To this end a protecting antibody level of > or = 45 EU/ml was selected as a level at which concentration most of the mice survived. Survival of mice in the MPT could be predicted, based on the antibody concentration at the day of challenge. Potencies estimated with the predicted and actual survival corresponded well (P = 0.990). This confirmed the essential role of vaccine induced pertussis antibodies in the protection against a lethal i.c. challenge and offered a possibility to develop a pertussis potency test based on serology. We developed a model in which mice (20-24 g) are immunized (i.p.) with graded doses of vaccine and bled after four weeks. Sera are titrated in Bordetella pertussis whole cell ELISA and potency based on vaccine dose dependent antibody response is estimated by means of a parallel line analysis. The potency of vaccines tested in the Pertussis Serological Potency Test (PSPT) and MPT are significantly similar, a P-value of 0.92 was found by means of the chi 2 test. Compared to the MPT, the PSPT is more reproducible as is indicated by its smaller 95% confidence intervals. Moreover, by using the PSPT the animal distress can be reduced to an acceptable level and the PSPT also results in a reduction of more than 25% in use of mice.

Animals↗

Clinical and serological studies in patients with Campylobacter fetus ssp. jejuni infection: II. Serological findings.

The serological responses of 53 patients with Campylobacter fetus ssp. jejuni enteritis were determined with formalinized, boiled and autoclaved antigen suspensions of four reference strains and the autologous isolate. Agglutinin titres of 400 or greater were found against both formalinized and boiled reference antigens in 64% of the patients. Using boiled reference antigens five seropositive patients were found who had not been detected with the formalinized reference antigens, and vice versa. Autoclaved antigens were less useful. The use of paired sera permitted the demonstration of a serological response in some additional patients, although their maximal titre did not exceed 200. The total number of patients with serological responses to reference antigens was thus 48 (91%). The use of autologous antigens detected only one further patient.

Antigen-Antibody Reactions↗